T-Alerts wrote:Newburyport Train 165 (3:15 pm from North Station) is stopped at Salem Station due to the malfunction of the Beverly Draw Bridge. Updates to follow.Affected direction: OutboundLast updated: Aug 18 2017 03:58 PM

There was an issue where the rails on the bridge span interface with the rails on the trestle -- the rails weren't going into place and locking up. Workers were able to get it lined up enough to resume service just in time to have minimal impact on the evening rush. They even got USCG approval to keep the bridge closed until after the last peak train.

Why its replacement wasn't a lift span is beyond me. It worked perfectly for the Thames River Bridge replacement project on the NEC 9 years ago I don't see how it wouldn't have worked here. You get a more reliable movable span along with a wider navigation channel all in one piece. The Kernwood Avenue truss swing bridge to the west is almost double the length of the RR bridge which means it's navigation channel is wider than that of a bridge that one has to pass through to get to the ocean. The 1A fixed bridge adjacent to the RR span was built to accommodate such a wider horizontal clearance.

I'm guessing there's a few reasons for that. It is probably cheaper to just replace the swing span instead of installing a whole new type of span, and it was definitely much faster than having to modify the trestle for a wider span as well. Also, widening the navigable channel could just mean more traffic and more openings.

Why its replacement wasn't a lift span is beyond me. It worked perfectly for the Thames River Bridge replacement project on the NEC 9 years ago I don't see how it wouldn't have worked here. You get a more reliable movable span along with a wider navigation channel all in one piece. The Kernwood Avenue truss swing bridge to the west is almost double the length of the RR bridge which means it's navigation channel is wider than that of a bridge that one has to pass through to get to the ocean. The 1A fixed bridge adjacent to the RR span was built to accommodate such a wider horizontal clearance.

But if you look at the fenders for the Kernwood St Bridge, the channel is only on one side of the center pier, resulting in about 55 feet of navigation (rough Google Maps look). The Beverly Draw has two channels on either side of the center pier both 40 feet in width, for 80 feet of navigation. They left the existing center pier and just replaced the swing structure and all the drive gear. Converting the type of bridge would have either resulted in a much more lengthy outage and/or an off-line build, both of which equal more money as BostonUrbEx hinted at. If they went off line, it might have made more sense to build a fixed structure of comparable height to the road bridge. But again, significantly more money. The current project was awarded under $20 million. And yes, that means they put the new bridge on a 130+ year-old pier.

To do a fixed span like the 1A bridge you would need significant grading at each end which for a RR would have to be much less steep than needed for a highway bridge, the grades would probably go all the way back to Beverly station and require that to be raised, not to mention wreaking havoc with the many grade crossings through town.

Avatar Photo - P&W local from Gardner to Worcester at Morgan Rd., Hubbardston

I believe someone on archBoston crunched it out and found that was possible to obtain the same vertical clearance as the 1A bridge with grades only between March St and School St (Congress St would then clear under just fine). The only thing is, on one side of the bridge there'd be a 2% grade, and on the other 1.5%. That's actually comparable to the Mystic River bridge further down the line, almost exactly. Considering it would eliminate openings entirely, and even a grade crossing along with it, perhaps it isn't too far fetched.

Bev Draw train traffic vs. openings are not approaching nearly enough of a conflict point that there'd be stratospheric benefit to going through the suffering and disruption of reaching for a fixed structure. A lift would've been a lot better than a swing in absolute terms because of faster movement, higher reliability, and potentially much wider shipping channel underneath simultaneously increasing the boat speed limit through the channel and lowering the duration of the raisings. But ultimately technical hurdles are going to determine if a switch in span type is feasible for the construction downsides, and that's not always the case when the last i's are dotted and t's crossed on the engineering assessment. The NEC Shoreline had swing bridge-for-swing bridge cleanroom replacements done at Shaw Cove and Mystic River during the first-wave 1980's high-speed upgrades because tight confines around the abutting marinas didn't allow for anything different without destructive property-taking from those very busy and economically-significant marinas.

Thinking far future when Purple Line schedules finally get Euro-dense, there's still enough finite limits to demand growth north of Salem that Bev Draw isn't going to become a constriction. Rockport's absolute frequency cap still has its ruling limit set by that branch's two movables, which can't be raised to fixed spans because of surrounding layout. And the development-curtailed nature of the intermediate 'burbs between downtown Beverly and downtown Newburyport means that N'port Branch demand (while substantially outslugging current frequencies) doesn't have a full-on exponential burst in it until you cross the Merrimack on another must-be-movable bridge to bring the NH Seacoast back online. There's still plenty of slack capacity left to tap for incremental service increases to the current terminus.

The most unlimited growth to tap is Salem-south served by Indigo/urban rail and the Blue Line extension, which makes Saugus Draw the bridge replacement that truly matters for eliminating the movable span. All BLX-Lynn concepts, including the ones that go through Point of Pines, opt for doubling-up onto the Eastern Route ROW on the Revere side of the river to pool the most expensive infrastructure onto one 4-track river crossing (i.e. the PoP option would cross the river via the shorter power line/ex-Eastern Revere Beach Branch causeway and merge with the Eastern main before the current bridge instead of shooting straight across next to Route 1A on the old BRB&L trajectory with its own independent full-length span). Which was determined to be more cost-effective and less environmentally disruptive because the Eastern RR did the draw approaches way back when at 4-track width with future expansion in mind, limiting the amount of environmental disruption to widen it. The river's also bereft of much boat traffic because of the ecological disaster of silt runoff in the second half of the 20th century that choked its channels to navigational uselessness for everything except the smallest power boats and occasional barge to GE. A replacement fixed bridge wouldn't need much additional clearance, because you simply can't thread a sailboat out of those sparsely-populated marinas with how narrow the channels have become between sandbars. So if they want to mount some expensive SGR effort, a fixed-span Saugus Draw replacement with 4-track abutments + 2-track deck you can slap a second set of Blue-carrying girders on later would be the present-day overpay that pays itself back when the time comes. Changing Bev Draw into something else slots much more as a "nice to have, but surplus-to-requirement".

The drawbridge seems to still be having some issues. Train 115 was held for about half an hour yesterday afternoon. I was on 167 right behind it, and we held at Salem. The conductor informed us that they were having trouble locking the bridge in place, but that staff was on-site to look at it, and they eventually cleared it for traffic.

Is this issue the same as what is widely reported on the swing bridge on the NEC going in to Pen Station where when fully closed the rails aren't lining up / locking in place properly? This is why they say they need to replace that bridge.

RenegadeMonster wrote:Is this issue the same as what is widely reported on the swing bridge on the NEC going in to Pen Station where when fully closed the rails aren't lining up / locking in place properly? This is why they say they need to replace that bridge.

That bridge– the Portal Bridge– is 107 years old so the likelihood of it having the exact same problem as the Beverly bridge is pretty small.